Community Water System · PWS MT0002121
North Davis Duplexes 421
Operator location Missoula, Montana - smaller served population (≤ 999) at 33 people served; 220 SDWIS violations on record from groundwater sources.
- 33
- People served (this PWS)
- 220
- EPA violations (this PWS)
- 24
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
North Davis Duplexes 421 standing, high SDWIS violation third
33 people served (SDWIS) - smaller served population (≤ 999). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 11% is middle-third health share (≤ 23%).
The verdict
North Davis Duplexes 421 sits in the upper third of the sitemap cohort by violation count (220), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (33; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 11% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- 220
- Total EPA violations on record
- 11%
- Health-based (MCL / treatment failure)
- 33
- People served by this PWS (SDWIS)
- N/A
- PFAS compounds detected (UCMR5)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
System Details
- System Type
- Community
- Owner Type
- Private
- Connections
- 13
- County
- Missoula
- School/Daycare
- No
- MCL Violations
- 24
- Monitoring Violations
- 191
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MCL | 24 | 2009 |
| Coliform (TCR) | MR | 7 | 2006 |
| Lead and Copper Rule | MR | 5 | 2007 |
| E. COLI | MR | 4 | 2016 |
| Arsenic | MR | 3 | 2002 |
| Barium | MR | 3 | 2002 |
| Cadmium | MR | 3 | 2002 |
| Fluoride | MR | 3 | 2002 |
| Nickel | MR | 3 | 2002 |
| Antimony, Total | MR | 3 | 2002 |
| Thallium, Total | MR | 3 | 2002 |
| Selenium | MR | 3 | 2002 |
| Toxaphene | MR | 3 | 2002 |
| Dalapon | MR | 3 | 2002 |
| Di(2-ethylhexyl) adipate | MR | 3 | 2002 |
| OXAMYL | MR | 3 | 2002 |
| Simazine | MR | 3 | 2002 |
| Picloram | MR | 3 | 2002 |
| Dinoseb | MR | 3 | 2002 |
| Hexachlorocyclopentadiene | MR | 3 | 2002 |
| Atrazine | MR | 3 | 2002 |
| LASSO | MR | 3 | 2002 |
| Heptachlor epoxide | MR | 3 | 2002 |
| 2,4-D | MR | 3 | 2002 |
| Pentachlorophenol | MR | 3 | 2002 |
| Chlordane | MR | 3 | 2002 |
| 1,2,4-Trichlorobenzene | MR | 3 | 2002 |
| Xylenes, Total | MR | 3 | 2002 |
| DICHLOROMETHANE | MR | 3 | 2002 |
| p-Dichlorobenzene | MR | 3 | 2002 |
Violation Count vs. the National Corpus
North Davis Duplexes 421 has 220 recorded EPA violations, 87% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 13% carry more. 11% of this system's own violations are health-based (24 of 220), and it ranks unranked by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
220 Higher than most more violations than 87% of 29,740 water systems
the national water-system corpus, bucketed by value
Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source EPA SDWIS · 2026-05-15
Population served record for North Davis Duplexes 421
EPA SDWIS lists 33 people served and 13 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.
Sources: EPA SDWIS
Nationwide peers
220 violations · 33 served: nearest cross-state SDWIS matches.
Cross-state systems with comparable violation load
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
What to do with North Davis Duplexes 421
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Montana compares on the same EPA violation measures. Montana systems
- Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
- Find and compare another public water system by name or PWSID. Search systems
EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.